What are the Change Brush Size shortcuts in Sculpt mode using Maya Navigation?
Ok, I've found them; the keys were bound to B for the size, Shift + B for the strength and Ctrl + B for the rotation of the brush.

To find this, I first switched to the default layout and searched for the actions bound to F, noted the entries were named 'Radial Control', switched back to the Maya layout and searched for that name.